Non-cytotoxic protection by human NK cells in mucosal secondary lymphoid tissues

Abstract

Even though NK cells have been named for their spontaneous cytotoxicity, a large subpopulation of human NK cells primarily responds to activation with cytokine secretion and not killing. These CD56brightCD16 NK cells are abundant in secondary lymphoid tissues, can restrict pathogens that have breached mucosal barriers, and assist Th1 polarization during immune response priming. This exciting new aspect of NK-cell biology is discussed in this viewpoint. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.